The present invention relates to a combination grinder and brewer for the grinding of coffee beans and the delivery of the ground coffee to a brewing chamber (also commonly referred to as a “brew basket”) for the brewing of a coffee beverage. More specifically, the present invention relates to a combination grinder and brewer in which a positive pressure air blanket is used to minimize the exposure of ground coffee to the moistened air produced in the brewing chamber as the ground coffee is delivered from the grinder and into the brewing chamber.
Apparatus for grinding coffee beans into ground coffee have found significant consumer acceptance, presumably due to the perceived freshness of the coffee produced with recently ground coffee. Many commercial establishments use combinations of coffee grinders and brewers or a single unit having the combined features to produce coffee of the freshness now being demanded by the consumer. Grocery chains have long recognized that many discerning coffee drinkers prefer to grind their own coffee at the store and thus have provided coffee beans and the necessary apparatus for the self grinding of the beans into ground coffee. The roasted coffee bean, however, produces along with the particles of ground coffee a very fine powder, primarily bean husk, called chaff fines that tend to float and separate from the main stream of ground coffee that emerges from the coffee grinder. During grinding and the associated creation of electrostatic energy, some of the chaff fines adhere to the surfaces of the grinder and other internal components of the combination grinder and brewer.
A combination grinder and brewer typically has the capability of grinding coffee beans as a coffee grinder discussed above, and additionally provides for the delivery of ground coffee to a brewing chamber. For example, U.S. Pat. No. 5,542,342 issued to McNeill discloses a combination grinder and brewer with a basket sensing mechanism to avoid the problem of ground coffee being delivered accidentally when no basket is present and includes a discussion of prior art constructions of combination grinders and brewers. However, in such constructions, since the coffee brewer is in close vicinity to the grinder, a gummy substance is often produced by the moistened air from brewing process coming into contact with the chaff fines. This gummy substance must be cleaned from the combination grinder and brewer frequently to provide for a clean appearance and proper functioning.
A number of proposed constructions are described in the prior art that claim to reduce the frequency of cleaning necessitated by the generation of chaff fines and the gummy substance resulting from the exposure of these chaff fines to moistened air. As examples of such devices, reference is first made to U.S. Pat. Nos. 4,833,642 and 5,042,731, each of which is assigned to the Bunn-O-Matic Corporation of Springfield, Ill. and describes a coffee grinder with a discharge chute of the type commonly found in grocery stores. The described grinders are provided with a chaff fine suppressor in the form of lever-like member. The chaff fine suppressor is attached to the discharge chute immediately adjacent the opening into the grinding mechanism. The chaff fine suppressor serves to dissipate electrostatic energy and prevent the chaff fines from separating from the main stream of ground coffee.
For an example of a moisture reduction device, reference is made to U.S. Pat. No. 5,444,434, which is assigned to Grindmaster Crathco Systems, the assignee of the present application. Specifically, a valve or “shutter” selectively closes the opening to the grinding mechanism during the brewing operation. This prevents the moistened air from the brewing process from travelling through the chute and into the grinding mechanism where ground coffee and chaff fines can absorb the moisture, resulting in the above-described “gummy” substance. While such a valve or shutter may lessen the problems associated with chaff fines, such valves or shutters may often “stick,” remaining open or closed due to the creation of a gummy substance at the juncture of the valve and chute. This “sticking” problem may cause jamming of ground coffee at the end of the end of the dispensing chute, which may ultimately result in failed solenoid coils, stalled grinder motors, or similar equipment failures.
In any event, despite various proposed constructions in the prior art, there remains a problem of ground coffee and chaff fines coming into contact with the moisture of the brewing chamber and adhering to the components and surfaces of the combination grinder and brewer. Thus, present applicants recognized that isolating the ground coffee from the moistened air associated with the brewing chamber could significantly reduce accumulation of ground coffee and chaff fines, and thus the creation of a gummy substance on the surfaces of the combination grinder and brewer.
It is an object of the present invention to provide a combination grinder and brewer with a construction that reduces the accumulation of ground coffee and chaff fines on its components and surfaces.
It is another object of the present invention to provide a combination grinder and brewer that effectively reduces the introduction of moisture from the brewing chamber into the ground coffee delivery system and grinder.
It is still another object of the present invention to provide a combination grinder and brewer that provides for improved dispersal of aroma resulting from the brewing process.
These and other objects and advantages of the present invention will become apparent upon a reading of the following description.